Government ministers are to be urged to investigate a South-ampton car clamp firm which is charging hundreds of pounds to release vehicles, with threats of a top-up fine for rudeness.

Southampton Itchen MP John Denham is calling on the Government to look into whether the firm is acting illegally.

He said the idea of car clampers charging excessive amounts to release vehicles and to charge motorists a £50 top-up fine if they think they are being subjected to “abusive or violent” behaviour creates a bad reputation for the city.

“The last thing the city needs at the moment is over-the-top action which gives the city a bad reputation for people to come to to shop and work,” he said.

Hampshire-based Whites Car Park Solutions Ltd is charging as much as £450 for parking in the wrong place. As well as a £150 release fee, motorists faced an extra £250 charge for a tow truck which drivers claim was called as soon as the clamp was placed on the vehicle.

Debbie Ludlam, 29, a community support officer from Locks Heath, found herself clamped after stopping in the HiQ garage in Northam for 20 minutes to tend to a sick baby.

When she asked how to pay the £150 release fee she was told to pay three times the charge as a tow truck had already been called. After calling the police the clamper came to an agreement for £275 to release the car.

Mortgage manager Nick Carr, 26, of Bitterne, was also clamped and charged £420 to get his vehicle free.

Labour MP Mr Denham said he understood the need to stop people parking on private land but added: “Excessive charges and aggressive companies create a bad image for the city.”

A House of Commons motion urging greater regulation of clamping on private land is already gathering cross-party support in Parliament, with the backing of 66 MPs.

A separate Home Affairs inquiry is reviewing the level of wheel-clamping on private land and the degree to which unreasonable penalties are imposed.

Mr Denham said he plans to take up the issue of excessive clamping charges with other Government ministers.

Clive Robertson, of Southamp-ton Trading Standards, said that as laws are unregulated, it is hard to take action against a clamping firm, and that it is down to individuals to take up the matter with civil action.

Jason White, owner of Whites Car Parking Solutions refused to comment.